At the bedside, the etiologist, like the primary physician, employs the medical history, physical examination, and laboratory to gain an understanding into disease processes. This proposal utilizes the clinical skills of the Principal Investigator supported by the expertise in cancer etiology found in the Harvard Medical School area, to discover new clues about the causes of cancer in man. The study procedure consists of screening the admission histories of all patients seen directly at the Sidney Farber Cancer Center or in consultation at adjacent hospitals, an intensive interview and physical examination of patients who may provide etiologic insights, and laboratory studies to identify etiologic mechanisms. The project will serve to provide the following: 1) new leads into carcinogenesis; 2) teaching of cancer etiology to staff; and 3) patient service through continued surveillance of high risk individuals.